1. Field
Embodiments of the present disclosure relate to a hydraulic brake system, and more particularly, to a hydraulic brake system for reducing pressure pulsation that is generated during operation of a pump.
2. Description of the Related Art
A hydraulic brake system is installed in a vehicle as an essential element to perform a braking operation. In recent years, various brake systems have been suggested to provide more strong and stable braking force.
Examples of the hydraulic brake system include an Anti-Lock Brake System (ABS) for preventing skid of wheels at the time of the braking, a brake traction control system (BTCS) for preventing slip of driving wheels at the time of a sudden acceleration incident or an unintended acceleration, and a vehicle dynamic control system (VDC) implemented as a combination of an ABS system and a traction control to maintain a stable driving state of a vehicle by controlling a liquid pressure of a brake.
Such a brake system includes a master cylinder that generates a required pressure for braking, a plurality of solenoid valves that control a braking hydraulic pressure transmitted to wheel brake sides, a low pressure accumulator that temporality stores oil, a pump and a motor that are configured to forcedly pump the oil temporarily stored in the low pressure accumulator, an orifice that reduces pressure pulsation of oil pumped by the pump, and an electronic control unit (ECU) that electrically controls operations of the solenoid valves and the pump. A valve assembly of the solenoid valves, the accumulator, the pump and the motor are installed in a hydraulic block (a modulator block), which is formed of aluminum, in a compact manner. The ECU is coupled to the hydraulic block while having an ECU housing in which a circuit board and a coil assembly of the solenoid valves are accommodated.
In the conventional brake system, a pump operation during a process of raising a braking pressure may generate a sudden pressure pulsation, which may be reduced by an orifice provided at an outlet side of the pump. However, the orifice only has a structure of reducing damping by adjusting a cross section of an oil passage, and thus there is a limitation as to reduce the pressure pulsation.